Tympan sheet for printing presses



May 5,1925.

s. E. DITTMAN 'MMPAN SHEET FOR 1511111111111 PnEssEs Filed May 10, 1923 fnl/@7170251- Patented May 5, 1925.

" UNITED STATES SAMUEL n.Y nrrrivmn, or criticano, iLLInoIs.

TYMPAN SHEET FOR :PRINTING- PRESSES.

Application filed May 10,

Iie it known that I, SAMUEL E. Drr'riuar, a citizen of the United States, residing at Chicago, in the county of Cook and State of Illinois, have invented a certain new and useful Improvement in Tympan Sheets for Printing Ihfesses, of Which the following is a full, clear, concise, and exact description, reference being had to the accompanying drawing, forming a part of this specification.

rIlle features of my invention reside in the provision of a resilient tympan sheet for printing presses which is inexpensive to manufacture, which may be stored for long periods Without deteriorating, Which eliminates the unyielding printing pressure Which is harmful to the plates, presses, and not conducive to a high quality of printing, and which retains its original resiliency and form throughout long periods of use.

The sheet is adapted for use either as a tympan packing sheet or as a draw sheet.

Iiiith these features and others, herein after appearing, in view the invention consists in the matters hereinafter fully described with reference to the accompanying drawing and more particularly pointed out in the claims.

In the said drawing-w Figure l is an enlarged transverse section of a portion of one form of the tympan sheet of my invention.

Figure 2 is a similarly enlarged partial face view of the same.

Figure 3 is an enlarged transverse section of a portion of another form of the tympan sheet of my invention.

Figure 4 is a similarly enlarged partial face vien7 of the sheet shown in Fig. 3.

Iiike characters of reference indicate like parts in the various views.

Itcferring to the drawing the sheet comprises a displacement space providing pattern of resilient material l interposed between tivo support sheets 2 conforming with and adhere-d to respective faces of the material. A material that I find is Well adapted for the purpose comprises one part of glycerine, tivo parts of corn starch, one part of rubber cement, and four parts of flexible glue boiled together and form-ed into the pattern While Warm. Of these fienibie glue by itself is also well fitted for the purpose. rIhis material retains its original resiliency 1923. Serial No. 638,070.

and normal form through long periods of use and has the proper degree of resiliency. rIhe sheets 2 are preferably tough fibrous paper, kraft or jute paper being Well fitted for the purpose, and these sheets 2 are preferably in'ipregna-ted with `sheliac which toughcns the paper and renders the paper sheets moisture proof to a large degl-ee, thus protecting the resilient material against moisture in addition to physically supporting, protecting, and maintaining the resilient material in its patterned form.

In Figures l and 2 a ribbed pattern is shown, and in Figures 3 and 4 a cellular pattern is shown which has certain advantages hereinafter referred to.

The tympan sheets may be used either for tympan packing or as draw` sheets in which case the pattern is perferably faced inwardly though it may be faced outwardly with a sheet of paper placed over the same to prevent the pattern o f the material showing on the printed product.

In use the tympan sheets are co1npressible under the printing impression and thus afford a cushioned printing pressure which reduces the Wear on the printing plates and press and lends to the quality of the printing. In addition the tympan sheets by reason of their reiliency and compression, under the printing pressure compensa-te for slight inaccuracies or irregularities of the press, plate base, and press packing.

The ribbed patterned sheet is preferably used with the ribs extending transversely of the impression cylinder, and the cellular patternedsheet is preferably used with the lines of material extending diagonally With respect to the impression cylinder. Then used in this manner creepage is prevented by reason of the fact that the patterns prevent an accumulation of the tension on the sheet circumferentially of the cylinder.

The cellular pattern has an additional advantage in that the air that is confined in the displacement space cells of the sheet, designated at 3, While under ron'ipression acts as additional yielding cushion and aids in the pattern returning to its normal form after compression.

It is obvious that one or more of the tympan sheets may be used as desired.

`While I have herein shown and particularly described the preferred embodiment of my intention I do not Wish to be limited to the precise details thereof as changes may readily bei made without departing from the spirit of my invention but having thus described my invention I claim as new and desire to secure by Letters Patent the following:

l. A tympan sheet comprising a displacement space providing pattern of resilient material interposed between two supporting sheets conforming with and adhered to respective faces of the material. A Q. A tympan sheet comprising a displacement space providing pattern of resilient material interposed between two sheets of paper conforming with and adhered to respective faces of the material.

A tympan sheet comprising a displacement space providing pattern of resilient material interposed between two sheets of fibrous material impregnated with shellac and adhered to respective faces of the material.

al. A tympan sheet comprising a displacement space providing pattern of resilient material interposed between two sheets of tough fibrous paper impregnated with a moisture proofing material and conforming with and adhered to respective faces of the material.

5. A tympan sheet comprising a displacement spaceproviding pat-tern of resilient material interposed between two sheets of tough fibrous pape-r im oregnated with shellac and conforming witii and adhered to respective faces of the material.

6. A tympan sheet comprising a cellular displacement space providing pattern of resilient material interposed between two supporting sheets conforming with and adhered to respective faces of the material.

7. A tympan sheet comprising a cellular displacement space providing pattern of resilient material interposed between two sheets of tough fibrous material impregnated with a moisture proofing material and conforming with and adhered to respective faces of the material.

8. A tympan sheet comprising a cellular displacement space providing pattern of' resilient material interposed between two sheets of tough fibrous paper impregnated with shellac and conforming with and adhered to respective faces of the material.

9. A tympan sheet comprising a displacement space providing pat-tern of flexible glue interposed between two supporting sheets adhered to respective faces of the material.

10. A tympan sheet comprising a displacement space providing pattern of flexible glue interposed between two sheets of tough fibrous material impregnated with a moisture proofing material and adhered to respective faces of the material.

l1. A tympan sheet comprising a cellular displacement space providing pattern of flexible glue interposed between two sheets of paper impregnated with shellac and conforming with and adheredto respective faces of the glue.

l2. A tympan sheet comprising a displacement space providing pattern of resilient material comprising a mixture of one part of glycerine, two parts of corn starch, one part of rubber cement, and four parts of flexible glue boiled together and formed into the pattern while warm, and two support sheets adhered to respective faces of the pattern of material.

3. A tympan sheet comprising a displacement space providing pattern of resilient material comprising a mixture of one part of glyeerine, two parts of corn starch, one part of rubber cement, and four parts of flexible glue boiled together and formed into the pattern while warm, and two sheets of tough fibrous material impregnated with a moisture proofing material conforming with and adhered to respective faces of the resilient material.

14. A tympan sheet comprising a cellular displacement space providing pattern of resilient material comprising one part of glycerine, two parts of corn starch, one part of rubber cement, and four parts of fiexible glue boiled together and formed into the pattern while warm, and two sheets of tough fibrous paper inpregnated with shellac and conforming with and adhered to respective faces of the material.

In witness whereof I hereunto affix my signature this eighth day of May, 1923.

SAMUEL E. DITTMAN. 

